Anti-Vesicular Nucleotide Transporter (VNUT Antibody) serum, from guinea pig

Solute carrier family 17 member 9 (UniProt; also known as Vesicular nucleotide transporter, VNUT) is encoded by the Slc17a9 (also known as Vnut) gene (Gene ID 228993) in murine species. VNUT is an anion transporter family member that mediates the active accumulation of nucleotides (i.e., ATP, ADP, and UTP) into secretory vesicles, as well as the exocytosis of ATP from various tissue types. VNUT is expressed by tyrosine hydroxylase-/TH-positive dopaminergic (DA) amacrine/interplexiform cells (IPCs) in the retina, as well as by both DA and non-DA neurons in the midbrain. In addition to the 447-amino acid Slc17a9 transcript (NM_183161), putative protein coding isoforms based on automated computational analysis have been predicted (X1, XM_006500589; X2, XM_006500590; X3, XM_006500591). Two protein bands of sizes ~75 and ~50 kDa are identified in mouse retinal and cortical tissues by immunoblotting, with the 75 kDa band being the 447-a.a. canonical VNUT isoform and the ~50 kDa band likely representing isoform X1/X2. In addition, a ~60 kDa form is also reported, representing either another spliced form or less glycosylated form. Murine VNUT is a 11-transmembrane (a.a. 40-60, 74-94, 103-123, 129-149, 169-189, 192-212, 252-272, 287-307, 327-347, 380-400, 413-433) vesicular protein, having an extacellular/vacuolar N-terminal end (a.a. 1-39) and a cytoplasmic C-terminal tail (a.a. 434-447) with 5 cytoplasmic and 5 extacellular/vacuolar loops in between.